In the printing process, more specifically the electro-photographic process, an image is typically transferred from a computer or other source to a print media. As part of the printing process, the image is created by the image source and may be etched electronically using a laser onto an organic photo conductor (OPC) drum. Etching the OPC drum may create areas on the OPC drum that are electrostatically discharged. As the OPC drum rotates, toner having oppositely charged particles may be transferred from a developer or presentation roller to the OPC drum. The toner may then be transferred to the print media and fused into the media.
As part of the printing process, excess or undeveloped toner may remain on the OPC drum. The toner can adhere to the OPC drum mechanically or through static electricity. Typically an elastic blade, commonly referred to in the industry as a cleaning blade or a wiper blade, is positioned against the OPC drum. The wiper blade is positioned to distribute pressure equally along the edge of the blade as the blade is positioned against the OPC drum. As the OPC drum rotates, the edge of the wiper blade scrapes off any excess toner that may be remaining on the OPC drum after the drum has transferred toner to the print media. The excess toner that is scrapped off the OPC drum is deposited in a waste bin section of the toner cartridge.
Removing the excessive or undeveloped toner may be complicated due to the surface roughness characteristics of the OPC drum. Surface imperfections on the OPC drum may allow the toner to become entrapped in areas where the wiper blade may not be able to adequately reach. This allows the waste or underdeveloped toner to pass underneath the wiper blade and become attached to the primary charge roller (PCR), resulting in various print defects. If the wiper blade does not effectively remove the excess toner, additive buildup of excess toner on the PCR may occur. The additive buildup insulates the PCR, reducing the charging capacity of the OPC drum. The reduced charge appears as a discharged area on the OPC drum resulting in toner being deposited into undesired areas of the OPC drum. This printing defect most often appears as vertical streaks in the direction the page travels during the printing process.
An emerging industry has developed that deals with the recycling of printer cartridges. Typically, the cartridge is recycled by a cartridge remanufacturer, who receives spent printer cartridges and refurbishes them. The refurbishment process entails replacing the worn or nonfunctioning parts, refilling the cartridge with either toner or ink, and distributing the refurbished cartridges into the marketplace. In some instances, different or newer toner may be installed in the original equipment manufacturer's (OEM) cartridges during the refurbishment process. Using different toner within an OEM cartridge may create printing difficulties due to possible incompatibility issues with the OEM cartridge.
As newer types of toners are developed, the characteristics of the toner may be different when compared to OEM toners. Newer toners may have different electrostatic charge characteristics as well as dimensional differences. For example, newer toner may be smaller or have different outline characteristics when compared to the OEM toner. An OEM imaging process cartridge with newer toner installed may not print properly due to problems arising from removing excess or waste toner from the OPC drum. In this instance, the OEM wiper blade may apply too little abutment pressure against the OPC drum to effectively remove the new toner.